FIG. 1 depicts the construction of a conventional scroll type compressor. Compressor 1 includes compressor housing 10 which comprises first cup-shaped casing 12 and second casing including front end plate 11 and tubular front boss 16. One end of first casing 12 is attached to one end surface of front end plate 11. A drive and compression mechanism are contained in a portion of compressor housing 10 defined by front end plate 11 and first casing 12.
Opening 111 receives one end of drive shaft 13 and is formed in the center portion of front end plate 11. One end of drive shaft 13 is fixedly connected to annular disc 14 which is rotatably supported in radial bearing 15. Radial bearing 15 is fixedly disposed in opening 111. The other end of drive shaft 13 extends through tubular front boss 16 which is fixedly secured on the other end surface of front end plate 11 by bolts 17. Radial bearing 18 is fixedly disposed on the inner surface of tubular front boss 16 for rotatably supporting the other end of drive shaft 13. Shaft seal mechanism 19 is disposed between the inner surface of tubular front boss 16 and the outer surface of drive shaft 13, and is adjacent to front end plate 11. Seal mechanism 19 seals the interior of compressor housing 10 from radial bearing 18, thereby preventing refrigerant and lubricating oil therein from leaking through tubular boss 16 to the outside of compressor 1.
Shaft seal mechanism 19 undergoes severe wear and breaks down more frequently than most any other part of the compressor. Consequently, shaft seal mechanism 19 is more frequently replaced than those other parts. Accordingly, it is desirable to enable one to easily replace shaft seal mechanism 19. However, replacement of shaft seal mechanism 19 embodied in the aforementioned compressor involves a series of complicated steps briefly described hereafter. The securement between front boss 16 and front end plate 11 is first released by unfastening bolts 17. Front boss 16 is then separated from front end plate 11. While pulling front boss 16 from front end plate 11, an annular shelf on the inner surface of front boss 16 pushes radial bearing 18 so that both front boss 16 and bearing 18 are removed from shaft 13 when front boss 16 is separated from front end plate 11. Shaft seal mechanism 19 is then removed from drive shaft 13. After a new seal mechanism is positioned on shaft 13, bearing 18 and boss 16 must be remounted.
The above replacement process is complicated and time consuming resulting in undesirable repair and maintenance costs. Furthermore, front boss 16 and front end plate 11 are separate components which require further assembly steps during the manufacture of the compressor. Consequently, the two component design can be cost ineffective for manufacturing process.